The objective of the Core is to scale-up and purify sufficient quantities of recombinant gamete antigens under good laboratory practice (GLP) guidelines for use as vaccinogens in immunogenicity and fertility trials in animal models and as assay target for monitoring immune responses. The aims/services provided are: 1. To clone the cDNAs for gamete antigens into appropriate plasmid vectors for expression in bacterial or mammalian hosts. 2. To grown the bacterial/mammalian cells expressing the recombinant gamete antigen in large quantities using 20 L or 80 L bioreactors under GLP guidelines. 3. To purify recombinant gamete antigens and perform assays to verify their retention of immunogenic epitopes, i.e., to determine if the recombinant protein has acquired appropriate folding and/or post- translational modifications. 4. To produce uniform vaccine doses by loading, filling and quantifying vaccine lots under standard operating procedures, including shipping and inventory.